New Flu Shot Approved By FDA

Editor's Choice
Main Category: Immune System / Vaccines
Also Included In: Flu / Cold / SARS
Article Date: 17 Jan 2013 - 11:00 PST


A new flu shot, Flublok, made using new technology, has just been approved by the U.S. FDA (Food and Drug Administration).

Flublok is the first trivalent influenza vaccine made using an insect virus (baculovirus) expression system and recombinant DNA technology.

Currently, the flu is quickly spreading across the United States. Public health officials have said the flu is now at "epidemic levels". The CDC (Centers for Disease Control and Prevention) advises everyone to receive a flu shot before the upcoming flu season.

The new vaccine has received approval for the prevention of seasonal influenza in people between the ages of 18 and 49. Flublok is made with a process that does not need the virus to be grown in chicken eggs, as current vaccines are currently made. This means that in case of a pandemic, the vaccine could be ready much earlier.

Large quantities of hemagglutinin (HA), the influenza virus protein, are produced by the Flublok's original manufacturing technology. HA is the active ingredient in all inactivated flu shots that is crucial for entry of the virus into the body's cells.

Most of the antibodies that stop the infection of the influenza virus are targeted against HA. Although the technology is new to flu vaccine production, it is used to make vaccines that have received approval from the FDA to prevent other spreadable illnesses.

Karen Midthun, M.D., director of the FDA's Center for Biologics Evaluation and Research, said:

"This approval represents a technological advance in the manufacturing of an influenza vaccine. The new technology offers the potential for faster start-up of the vaccine manufacturing process in the event of a pandemic, because it is not dependent on an egg supply or on availability of the influenza virus."

In order to recognize strains that may be the source of most sicknesses in the approaching season, the World Health Organization (WHO), the FDA, the CDC, and other public health specialists work together each year to analyze influenza disease surveillance and laboratory data gathered worldwide.

The FDA chooses the various flu strains each year that U.S. manufacturers should include in their vaccines for the upcoming flu season by using the data analyzed, as well as the suggestions made by the FDA's Vaccines and Related Biological Products Advisory Committee.

When the strains in the vaccines match the flu virus strains in circulation, people are much better protected from getting the flu.

Flublok protects againsts two influenza virus A strains, H1N1 and H3N2, and one influenza virus B strain, because it consists of three, full-length recombinant HA proteins.

The vaccine will be assessed each year by the FDA, as it does with all other flu shots, before the public receives it each flu season.

The FDA will evaluate the recombinant HA proteins that are produced in the baculovirus expression system and included in the new vaccine.

Research conducted at different locations in the United States analyzed the effectiveness of Flublok. Approximately 4,600 people participated in the study, half received Flulbok and the other half were given a placebo.

Results showed that Flublok not only protected against the 3 matched strains that were contained in the shot, but was also found to be 44.6% effective against all circulating influenza strains.

The vaccine's safety was assessed in a study consisting of an estimated 2,500 people who received the shot.

The adverse reactions that were reported most frequently included:

• headache
• pain at the injection-site
• fatigue
• muscle aches

Those events are also common for traditional egg-based, inactivated flu shots.

Physicians need to check the expiration date before administering Flublok to patients. From the date of manufacture, it has a shelf life of 16 weeks.

The vaccine is manufactured by Protein Sciences Corp., of Meriden, Connecticut.

Written by Sarah Glynn
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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